Hydraulic precision lathe



July 21, 1936. L. F. COLLINS HYDRAULIC PRECISION LATHE Filed Oct. 22, 1952 3 Sheets-Sheet 2 INVENTOR LEO F COLL/N5 BY 2 D ATTORNEY July 21, 1936. co s 2,048,107

mmmumc PRECISION LATHE Filed Oct. 22, 1932 s She'ets-Sheet s r /02 INVENTOR LEO f COLL/N5 a v P/MW ATTORNEY "all Patented July 21, 1936 UNITED STATES PATENT OFFICE HYDRAULIC PRECISION LATHE Leo F. Collins. Seattle, Wash. Application October 22, 1932, Serial No. 839,022.

lclaim.

This invention relates to improvements in lathes, and moreparticularly to lathes of the screw cutting precision type; it being the principal object of this invention to provide a lathe ofthe above character in which the movement of the cutter or tool is produced andcontrolled by hydraulically actuated-mechanism.

More specifically stated, the present invention resides in the provision of a lathe in which the tool holding block is mounted for movement under the individual control of a main feed hydraulic cylinder and a cross feed hydraulic cylinder; the said cylinders including their piston assemblies, connecting tubes for application of the fluid pressure medium and certain novelcontrol valves whereby the direction of flow and amount of flow may be finely adjusted so as to positively and accurately control the movement of the tool.

Another object of the invention is to provide an automatic hydraulically actuatedmeans for offsetting the tool or cutter from the work for the return stroke and to make this reversible so as to adapt it for either external or internal work.

Other objects of the invention reside in the details of construction of the various parts, in their combination and mode of operation, as will hereinafter be more fully described.

In accomplishing these and other objects, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein Fig. 1 is a front elevation of a lathe equipped with mechanism in accordance with the present invention.

Fig. 2 is a plan view of the same.

Fig. 3 is a cross section, taken substantially on the line 3-3 in P18. 1.

Fig. 4 is a longitudinal sectional view of the main feed cylinder.

Fig. 5 is an end view of the same. I

Fig.6isaview callyillustrating the hydraulic control cylinders, control valves and piping connections.

Fig. '7 is a longitudinal section'of one of the feed control valves.

Fig. Bisacrosssection onlinel-linFig. 7.

Fig. 9 is a longitudinal section of the reversing valve.

Fig.10isacrosssectiononlineil-llin Fig. 9.

Fig.11isalongitudina1sectionoi'thescrew matting control valve.

Fig. 12 is a cross section of the same taken on line l--|I in Fig. 11.

Fig. 13 is a horizontal section of the cross feed cylinder.

Fig. 14 is a sectional view of the off valve.

Fig. 15 is a side view of the feed adjustment.

Fig. 16 is a plan view of the same.

Referring more in detail to the drawings- The present lathe comprises the usual bed frame structure I supported by legs orend frames 2--2 at a suitable working height. At one end is the usual head stock 3 with stepped pulleys l for obtaining various driving speeds and at the opposite end is the tail stock 5. The pulley shaft of the head stock carries the face plate 6 with a chuck i for mounting the work, and the tail stock carries a center 3 which may coact with parts 6 and 'I to mount the piece to be worked on.

Slidably mounted on the bed frame for travel longitudinally thereon is a carriage l0, and slidably mounted-on this carriage for travel in a diautomatic cut rection transversely of the bed frame is the cross feed plate H on which the tool mounting block it is fixed. The cutter or tool. as designated at I3 is adjustably mounted in a support i4 adjustable on the block in the usual manner to provide for its being set for operation on pieces of various shapes.

AswillbebestseeninFig.3,the carriage "is held in proper alinement by the provision of inverted V-shaped grooves ii in its under side which slidably receive correspondingly shaped and parallel ribs I. on the bed frame. Clips ll attached to the carriage slidingly engage beneath flanges ll of the frame to prevent any upward displacement of the carriage. This carriage rigidly mounts the main feed cylinder "which is disposed parallel with and adjacent the forward side of the bed plate-as seen best in Figs. 1 and 2. Within the cylinder is a piston 22, as seen in Fig. I, to-which is fastened a piston rod 23 slidable through a packed gland 24 in the cylinder head I. The outer end of the rod 23 is flxedtoabracketflthatisrigl yfastenedto frame I. cylinder l3 mount two parallel manifolds 23 and 2! of tubular character from which pipe connecmteendheadsllandllolthe tionsaremadewithareguiatingvaiven. As-

' manifolds will be maintained for all positions of movement of the cylinder II and carriage in its travel lengthwise of the machine.

A prusure medium supply pipe II connects with pipe II adjacent the bracket II and likewise an outlet or exhaust pipe II connects with pipe II.

The cross feed cylinder 20 is rigidly secured to thesIideII asseeninl'igjandpressuremedinm is admitted thereto'under control of a valve A from the supply through the manifold II. As seen in Figs. 6 and 18, the cylinder II contains a piston II' and this has two hollow or tubular piston rods II 'and III; fixed thereto and extending'through the inner end of the cylinderlwhere they are fixed against movement by a connection presently described, with the main frame. The pisto'nrodII extendsthroughthepis'toninopen communication with the chamber at the outer end of the cylinder, and piston rod III: has a portIIbopeningintothecylinderattheother sideof the piston.- 7

Control valve A is connected at diametrically opposite points of its upper end with the manifolds II and II respectively: one connection comprising the pipes III and III. as-seen in Fig. 8, and the other connection comprising pipes III and III. ,The valve A Is also connected at diametrically opposite pointsof its lower end with the hollow piston rods II and III: respectively;

one connecflon comprising pipes III and III, and the other comprising 919 III and III.

ThevalvesAandBmaybemanipulatedtoregulate the flow of pressure medium tothe cylinders II and II to thereby control the rate of travel of the cutter. These two valves are of like comtructionandareofthetypeillustratedin Figs. 7 and 8 wherein III designates a cylindrical valve housing provided at its upper end with diametrIc ports III and III and at its lower end with diametrie ports III and, III. .Valve A recetvesthepipes III, III, III and III respectively in thp-ports III III. IILand III-Yalvellikewisei'eceives the pipes III, III, III and III into 'theseports.

In the cylinder in. is revolubly mounted a helical orscrew shaped core III provided with islands II'I (in-Fig. 8). The top of the core is pI'ovidedwIthashankIIIandanoperatinghandleIII. Thecoreisaxiaily heldin place by a cover III screwedonto the cylindrical body III. Promtheaboveitwillbeapparentthatwhen islands III registu'with ports III-III thevalve willbeinoperative,anditwillalsobenotedthat thecoreisrotatedthattheprcssuremedium madetopassfrom port III,whichwill maybe nowbeconsideredtheintakeport,toportlIIor iIIdependingonthei-otationontheoore III.forexampIeinI"ig.7thecorebeingrotated aeahown the pressure medium will flow from IIIandareturnIngpreasuremepart III and pass up to port. III. rotated in the opposite direction,

eccentric a lever II is fixed, the outer end of the lever being pivotally connected to the end of a piston rod II attached to a piston II operable in a cylinder II supported from frame I as seen in Fig. 3. Oppomte ends of this cylinder have. pipe 5 connections III-III leading respectively to upper and lower ports of a reversing valve D connected by pipes III'-III' with pipes III and III. The purpose and operation of this valve will presently he described in connection with the tool offsetting operation. There is also a reversing valve 0 interposed in the. connections with valve A. and it has a connection III leading to pipe III, a pipe III leading to pipe III, and connections "Id and IIIa. leading to opposite ends of a cylinder III which, as seen in Fig. 14, contains a piston I" connected by rod III to avalve III which controls flow of medium through valve F in the pipe connection between manifold II and valve 8.

The valve 1'' consists of a casing connected at opposite ends with pipes III and III and having a dividing wall III provided with a passage seating valve III. Pressure may enter the cylinder IIIi'rom pipe III to act on piston III to unseat the valve to permit flow to pipe III;

ThesereversingvalvesCandDareofthetype shown in Fig. 9. Each consists of a hollow cylindrical body III provided with ports III-III at diametric points in its upper end and ports III-III at .diametric points in its lower end. ThevalveDreceivesthepipes III '-III, III and III respectively into these ports III, III, III and III. ValveC receives the pipes III'-IIIa, III and "In, respectively, into these ports in the order enumerated.

Within the casing III a core III is rotatably mounted and this is provided with holes III-l II andvalveBasseeninPig.6. Tbevalvehousing 30 is connected at its upper end by pipe III with pipe III and at its lower end by pipe III with pipe I".

This valve comprises-a body III with a cored outchamber III Thebottom ofthehodyis providedwithaport IIIa'andthesidewitha port IIIb which, respectively. receive the pipes IIIandIII. Thetopandbottomofthechamber areturnedoutasshownatIIIandIIltoreceive, ahollowaleeve III (seel'igJI) pressediirmlyin place. Thissleeveisprovidedwithlongitudinal,

narrowslitsIII. OntheinsideofthesleeveIII is rotatably mounted a hollow cylindrical core IIIthebottomofwhIchisopenandflietop chsedmllprovidedwithashank III towhich-Is secured a worm gear I32 which coacts with a lead screw 21 of the turning lathe. The walls of this cylindrical core are provided with slits I33.

which will register with slits I29 with the sleeve I28 when properly turned, as shown in Fig. 12, and in which position the pressure medium may pass from port I25a into hollow core I30 through slits I33 of the core, slits I29 of the sleeve I28 into chamber I25 and to port I255.

Briefly referring again to the piping diagram shown in Fig. 6, I is a pipe connecting from manifold 28 and branches into two pipes I42 and I43, pipe I42 connecting with inlet port I02 of valve A which is of the type shown in Fig. '7. Port I04 connects with pipes I44 and I45 to hollow piston rod 45a. Port I05 connects with pipes I45 and I41 to hollow piston rod 45, and port I03 connects with pipes I48, I49 and I50 to manifold 29. Pipe I43 connects with port I02 of valve B which is of the same type shown in Fig. 7. Port I04 as shown in Fig. '7, connects with pipes I5I and,I52 to right hand end of car- 'riage cylinder I9. Port I05 connects with pipes I53 and I54 to the left hand end of the cylinder I9.

The reverse valves C and D, as shown in Fig. 6, are of the type shown in Fig. 9 and are connected in the pressure circuit as shown in Fig. 6. The

screw cutting valve E of Fig. 6 is the same as the valve shown in Fig. 11. The valve F with its control is the same as the valve shown in Fig. 14. The reference numerals for the ports of valves C, D, E and F are the same as those used in the corresponding Figs. 9, 10, 11, 12 and 14.

In the use of'the machine for all ordinary tuming, or when the carriage is moving longitudinally with the lathe, only valve B is used. Assuming the core of the valve to be in the same general position as shown in Fig. '7, the pressure circuit is as follows- The pressure medium enters pipe 40, passes through-pipe 32. into manifold 28 through pipes HI and I43 to port I02 of valve B, through the valve to port I04 to pipes I5l and I52 into right hand end of cylinder I9, causing it, and consequently the entire carriage with all its attachments such as piping valves, etc., to move to the right. The pressure medium in the left hand end of the cylinder I9 will be forced into pipes I54 and I53 to port I05 of valve B, through the.

valve to port I03 to pipes I51 and I5I through valve F through pipes .I52 and I49 andv I50 to manifold I29 and back to the source. ,Upon reaching the end of the cut, valve- D is opened, thereby causing hole I H to register with ports I I2 and H3, or at an angle of ninety degrees from the position shown in Fig. 9, so the pressure medium will pass from pipe I5I to port II2 through the valve to port II3 through pipe I55 into the inner end of the cylinder 55 turning the lever 53 so as to rotate the eccentric 50 in such-a manner as to pull the piston rods 45-45a inwardly pulling piston 45 and cylinder 20 inwardly, carrying with it the cross feed with the tool a slight distance away from the work. The reason for the cylinder moving with the piston is due to pressure medium being trapped between the piston 45 and the inner end of cylinder 20. 1 The tool being relieved from the work, the valve B is reversed, in which case the pressure medium passes from port I02 through the valve to port I55 through pipe I 53 and I54 into the left hand end of the cylinder I9 returning the carriage with the tool to the left, thus returning the tool to the beginning of the cut. Valve D is nowreversed allowing the tool to come in contact with the work. For internal turning, valve D is turned in the reverse direction from that described above causing the reverse action of piston 55 and lever 53 which in turn pulls the tool away from the cut.

Assuming it is desired to operate the cross feed such as turning the face of a disk, valve A is used, the rest remaining closed. The valve A being turned in the reversed direction from that shown in Fig. '7 the pressure medium will pass from manifold 20 through pipes MI and I42 to port I02 of valve A, through the valve to port I05, through pipes I45 and I" into hollow piston rod 45 into the outer end of cylinder 20 causing it to move outward which in turn feeds the tool inwardly toward the center of the lathe; the cylinder 20 and the tool being located on the opposite side of the work. Upon reversing valve A, or to the position shown in Fig. '7, the reverse action takes place and the tool is returned to the outside edge of the work.

Supposing it is desired to turn thread, valves A and C are operated so that as the pressure medium passes from valve A by either pipe I45 to port II2 of valve C, or through pipes I44-I55 to port I I5 of valve C; in either case the valve C is set so that the pressure medium passes through port I I3 into the left hand end of cylinder I38 closing the valve F, as seen in Fig. 14. As the lathe is set-in operation and the lead screw set for the proper thread, worm gear I32 of valve F will be rotated turning the core of the valve so as to permit the returning fluid to valve B to pass from port I03 through pipe I51 and I58 to the bottom of valve E through the core from the sleeve .to outlet port I25b through pipe I59- I50 to manifold 29. As soon as this valve is set into operation the motion of the carriage moves the valve E with it, and this relative movement between the carriage and the lead screw will turn the worm gear I32 in the opposite direction so as l carriage movable longitudinally along the frame,

a slide .on the carriage movable transversely of the frame, a work engaging tool mounted on the slide, a cylinder fixed to the carriage and extending longitudinally of the frame, a cylinder fixed to the carriage and extending transversely of the frame, a piston in each cylinder, the piston of the first cylinder having a fixed connection with .the frame, an eccentric mounted by the carriage and connecting the piston of the second cylinder therewith and individual means. for controlling an application of pressure medium to each cylinder for affecting its movement in either direction at a controlled speed and a hydraulic cylin-- der connected in the said last mentioned means and having a piston automatically operable incident to reversalof direction of fiow in the first cylinder to rotate the eccentric .to movethe slide to offset the tool from the work.

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